It's Friday night in Hornsea, a small village in East Yorkshire; the air is cold and the stars seem to go on forever. Just off the High Street, a small accountancy firm is closing up; Andy, a man who loves the challenges of VAT, has finished the filing, and is having a cup of tea, chatting on the phone to a friend about the plan to save the Floral Hall. Suddenly a siren blasts out. It's coming from a mobile phone, connected directly to the ambulance service. Andy is not a paramedic, but he is a Community First Responder - someone trained in life saving techniques, who has volunteered to drop everything to go and be the first on the scene in an emergency. The actions he takes over the next few minutes could mean the difference between life and death. Within seconds he's donned a high-vis jacket and, weighed down with a rucksack of life saving equipment, is running for his car. By the time the ambulance services arrives from the nearest hospital he may have been at the scene for some time - administering life-saving first aid. First Responders come from every walk of life, and are all highly trained volunteers. But it's a huge commitment, and responsibility, and over Christmas and New Year, a busy one. So what motivates someone to take on such a role? Good Samaritans on the surface, but is it the adrenalin rush many say they feel that makes them addicted to saving lives? Julie Gatenby meets the Community First Responders of East Yorkshire. Producer: Sara Jane Hall.